Patent Document 1 and Patent Document 2 describe examples of resource allocation technology. A virtual computer (machine) system described in Patent Document 1 is composed of a load monitor which measures load of OS (Operating System) on LPARs (logical partitions), a user interface by which a manager sets knowledge related to OS workload of OS, and an adaptive controller which changes degrees of allocating resources by calculating resource allocation rate for each LPAR based on values of the loads and settings and directs the hypervisor to change resource allocation.
In the virtual machine system described in Patent Document 1, LPARs are started at an initial setting. And then, the adaptive controller calculates the resource allocation rate which is within a setting range for each LPAR, so that performance increases based on forecast workloads inputted through the user interface and/or a load measured by the load monitor. Resource allocations are changed by directing the hypervisor to change into calculated resource allocation rate. Therefore, this system can change adaptive resource allocation in response to loads of OSs.
This kind of resource allocation system has a problem that a service to be must be determined in advance. For example, in the virtual machine system of Patent Document 1, computer resources are allocated evenly based on forecast service required amounts for each LPAR, and then, loads are observed and computer resources are adjusted based on the resource load amount. In such systems, there is no consideration for some additional space, for example idle resource amount stocked for allocating new LPARs.
However, services should be run in response to user's demands, and the number of services run is not always fixed. Consequently, resource provisioning system in response to a user's starting demands for service is desirable.
In view of the above description, a resource allocation system that limits resource allocation is proposed. Patent Document 2 is an example of a resource allocation system that limits resource allocation when a shared resource is provided to a plurality of clients.
The system described in Patent Document 2 is composed of a resource provider which encodes restrictions on aggregated usage amount of a resource allocated to one or more clients, and a resource manager that validates and arbitrates requests to allocate resources to the one or more clients by a resource provider based on budgets. The resource manager notifies clients of availability and shortages of resources, to promote compliance with the restrictions encoded in a hierarchical budget(s).
Here, the budget is managed according to a budget limit “L” which is the maximum amount that can be allocated to one client, a budget commit “C” which is the amount of a resource already allocated, and a budget reservation “R” which ensures that a future demand to allocate a resource for one client will likely succeed. A client connected to a budget is provided with a resource amount, which is the budget commit, while adjusting to secure the budget, in a range that does not exceed the budget limit. The budget(s) can be formed in a hierarchy, and by further collecting an aggregation of budgets as one budget, resource management by the budget limit, the budget commit, and the budget reservation, is made possible. By assuring the likelihood of securing a resource by securing the budget and avoiding securing all the resources by the budget limit in this way, an operating environment in which prediction is more feasible is provided, so that more efficient resource management becomes possible.
[Patent Document 1]
JP Patent Kokai Publication No. JP-P2007-200346A
[Patent Document 1]
JP Patent Kokai Publication No. JP-P2006-236351A